Yandere! Younger Brother & Reader (Older Sister)

Watched

Saiyo begun to nag for you to not leave him alone. He would hug your arm and not let go! Rubbing against you, he'd place soft kisses on your arm.
He would stay beside everywhere you went in the school; with the exception of the bathroom, of course! You told him you could manage by yourself, but he shook his head that he wouldn't allow it.
"Come on! I want to hang out with my friends alone", you whined to him.
"But (Y/N)! What if they turn on you and hurt you!"Saiyo pleaded as he glared at your buddies.
"That won't happen! Besides if they did, they wouldn't be my friends. " You walked away from your brother. His expression hurt.
You knew what you did didn't stop him from following you. You and your friends came to a park. His eyes burned straight through you. You tried to go on with having fun, but you couldn't shake the feeling of his hawk eyes off yourself.
"Sakura, I think I'm going to go home." You told your friend.
"But we've been here for so little, are you sure?" Asked Martha.
"Yeah, I don't feel so well."
You said your goodbyes and headed home. The hot gaze of your brother made you hurry.
You crossed many streets and finally made it back. You opened the front door and found your brother awaiting your arrival. He put his hands behind his back then grinned at you. You shifted uncomfortably as you stared at him in horror.
"Welcome back sis!" He greeted warmly.
"I missed you so much that I thought I might die without your presence! Did you have fun with your friends? " You knew he was just being friendly, but you couldn't help but feel something dangerous lingering from him.
You answered quietly.
"I left early because my stomach hurts."
"Aww! Don't go getting injured without me there to punish them!" He said deeply.
Something wasn't right.
You slept restlessly that night. Saiyo haunted your dreams. Every dream became the same nightmare. You would have him cuddling you while saying inaudible words. Blood would rain over you two, soaking you're clothes.
"Your brother isn't the same" you whispered to yourself.
You rolled in your covers. The cold night couldn't compare to your charred bones.
If the world is _______. Life should be too.